I came across this travel site that has some very interesting data. It’s called farecast. It collects the amount that airline tickets have gone for in the past and then maps out the trend in the pricing so that you can choose different times or dates according to which should be cheaper. It is another way of finding good deals and seeing when to get tickets rather than just looking for what is the best deals as of this minute. They are just rolling out international flights and have started hotel rates as well. It has the usual search functions similar to kayak.com but the real use is the smart predictions. The only drawback is that the predictions only work for only certain cities, but it looks like they are added new ones periodically.

You can read about it more in this NY Times article.